186 TEE ZOOLOGIST. 



ance on the Eock until August 28th, and I did not detect the 

 regular movement setting in until September 1st. The same 

 may be said of Swallows. The regular migration did not start 

 until August 30th. Prior to this, however, I had seen odd 

 Swallows flitting past at uncertain intervals. From the point 

 of view of obtaining rest it was fortunate that the migration 

 of the above-mentioned birds set in during part of a bright 

 lunar phase, on which nights the rays of the lantern were 

 rendered too feeble to allure migrants, and so visiting the 

 balcony for many hours was not the most profitable way of 

 spending time. It also happened that, as the moon gradually 

 waned and the dark phase was entered upon, very few birds 

 appeared near the lantern, owing to the prevalence of wind and 

 clear atmosphere. Indeed, it was not until the last lunar 

 quarter was almost complete that migrants began to appear in 

 any conspicuous numbers in the rays. This was on the night 

 of September 11th, 1912, from which date, until the end of the 

 month, I renewed my nocturnal watches at the lantern with 

 much regularity, the weather conditions and lunar phases on 

 the whole lending themselves to favourable results. To return 

 to my observations on the migratory movements of Wagtails, 

 Pipits, and Swallows. The daily time of their passage over 

 the Eock was ushered in with marked regularity. Wagtails and 

 Pipits appeared almost synchronously with the ascent of the 

 sun over the horizon, though it was not exceptional to see the 

 birds before sunrise. Swallows were more wont to arrive an 

 hour or two later, but this event also exhibited variation in time 

 within certain limits. At first I used to watch the birds from 

 any point on the Eock. Thinking, however, that my presence 

 might iu any way interfere with the natural inclination of the 

 direction or speed of their flight, I decided to keep ambushed in 

 a crevice, where at the same time I could fairly well command a 

 good view of the greater part of the Eock. I certainly found, as 

 far as Wagtails and Pipits were concerned, that by adopting 

 this form of strategy more birds descended and alighted than 

 when I stood up and discarded concealment. Eoughly speaking, 

 about 5 per cent, of the total number observed tarried on the 

 Eock. This percentage was taken in the aggregate; daily it 

 varied markedly. Thus, on warm, calm days, as well as on 



